Approximate evaluation of cochler model frequency selectivity from the wave development graph

Evaluation of the tuning quality $Q_N$ from the response-versus-eigenfrequency graph is considered. It is shown that factor $Q_N^{(\omega_0)}$ analogous to $Q_N^{(\omega)}$ but measured in eigenfrequency scale may approximate tuning quality if two conditions are hold: (i) the tuning is sharp enough ($Q_N\gg1$) and (ii) fluid energy in the peak vicinity is much less then partition kinetic energy.